Arquivo mensal: junho 2017

Why did humans evolve such large brains? Because smarter people have more friends (The Conversation)

June 19, 2017 10.01am EDT

Humans are the only ultrasocial creature on the planet. We have outcompeted, interbred or even killed off all other hominin species. We cohabit in cities of tens of millions of people and, despite what the media tell us, violence between individuals is extremely rare. This is because we have an extremely large, flexible and complex “social brain”.

To truly understand how the brain maintains our human intellect, we would need to know about the state of all 86 billion neurons and their 100 trillion interconnections, as well as the varying strengths with which they are connected, and the state of more than 1,000 proteins that exist at each connection point. Neurobiologist Steven Rose suggests that even this is not enough – we would still need know how these connections have evolved over a person’s lifetime and even the social context in which they had occurred. It may take centuries just to figure out basic neuronal connectivity.

Many people assume that our brain operates like a powerful computer. But Robert Epstein, a psychologist at the American Institute for Behavioural Research and Technology, says this is just shoddy thinking and is holding back our understanding of the human brain. Because, while humans start with senses, reflexes and learning mechanisms, we are not born with any of the information, rules, algorithms or other key design elements that allow computers to behave somewhat intelligently. For instance, computers store exact copies of data that persist for long periods of time, even when the power is switched off. Our brains, meanwhile, are capable of creating false data or false memories, and they only maintain our intellect as long as we remain alive.

We are organisms, not computers

Of course, we can see many advantages in having a large brain. In my recent book on human evolution I suggest it firstly allows humans to exist in a group size of about 150. This builds resilience to environmental changes by increasing and diversifying food production and sharing.


As our ancestors got smarter, they became capable of living in larger and larger groups. Mark Maslin, Author provided

A social brain also allows specialisation of skills so individuals can concentrate on supporting childbirth, tool-making, fire setting, hunting or resource allocation. Humans have no natural weapons, but working in large groups and having tools allowed us to become the apex predator, hunting animals as large as mammoths to extinction.

Our social groups are large and complex, but this creates high stress levels for individuals because the rewards in terms of food, safety and reproduction are so great. Hence, Oxford anthropologist Robin Dunbar argues our huge brain is primarily developed to keep track of rapidly changing relationships. It takes a huge amount of cognitive ability to exist in large social groups, and if you fall out of the group you lose access to food and mates and are unlikely to reproduce and pass on your genes.


Great. But what about your soap opera knowledge? ronstik / shutterstock

My undergraduates come to university thinking they are extremely smart as they can do differential equations and understand the use of split infinitives. But I point out to them that almost anyone walking down the street has the capacity to hold the moral and ethical dilemmas of at least five soap operas in their head at any one time. And that is what being smart really means. It is the detailed knowledge of society and the need to track and control the ever changing relationship between people around us that has created our huge complex brain.

It seems our brains could be even more flexible that we previously thought. Recent genetic evidence suggests the modern human brain is more malleable and is modelled more by the surrounding environment than that of chimpanzees. The anatomy of the chimpanzee brain is strongly controlled by their genes, whereas the modern human brain is extensively shaped by the environment, no matter what the genetics.

This means the human brain is pre-programmed to be extremely flexible; its cerebral organisation is adjusted by the environment and society in which it is raised. So each new generation’s brain structure can adapt to the new environmental and social challenges without the need to physically evolve.


Evolution at work. OtmarW / shutterstock

This may also explain why we all complain that we do not understand the next generation as their brains are wired differently, having grown up in a different physical and social environment. An example of this is the ease with which the latest generation interacts with technology almost if they had co-evolved with it.

So next time you turn on a computer just remember how big and complex your brain is – to keep a track of your friends and enemies.

Groups are often smarter without ‘opinion leaders’ (Futurity)

Equality may counteract the tendency toward groupthink, research suggests.

The classic “wisdom of crowds” theory goes like this: If we ask a group of people to guess an outcome, the group’s guess will be better than any individual expert. So, when a group tries to make a decision, in this case, predicting the outcome of an election, the group does a better job than experts. For market predictions, geopolitical forecasting, and crowdsourcing product ideas, the wisdom of crowds has been shown to even outperform industry experts.

“On average, opinion leaders were more likely to lead the group astray than to improve it.”

That is true—as long as people don’t talk to each other. When people start sharing their opinions, their conversations can lead to social influences that produce “groupthink” and destroy the wisdom of the crowd. So says the classic theory.

But Damon Centola, an associate professor in the University of Pennsylvania’s Annenberg School for Communication and School of Engineering and Applied Science and director of the Network Dynamics Group, discovered the opposite.

When people talk to each other, the crowd can get smarter, report Centola, PhD candidate Joshua Becker, and recent PhD graduate Devon Brackbill in Proceedings of the National Academy of Sciences.

Equal influence

“The classic theory says that if you let people talk to each other groups go astray. But,” says Centola, “we find that even if people are not particularly accurate, when they talk to each other, they help to make each other smarter. Whether things get better or worse depends on the networks.

“In egalitarian networks,” he says, “where everyone has equal influence, we find a strong social-learning effect, which improves the quality of everyone’s judgments. When people exchange ideas, everyone gets smarter. But this can all go haywire if there are opinion leaders in the group.”

An influential opinion leader can hijack the process, leading the entire group astray. While opinion leaders may be knowledgeable on some topics, Centola found that, when the conversation moved away from their expertise, they still remained just as influential. As a result, they ruined the group’s judgment.

“On average,” he says, “opinion leaders were more likely to lead the group astray than to improve it.”

Gut responses

The online study included more than 1,300 participants, who went into one of three experimental conditions. Some were placed into one of the “egalitarian” networks, where everyone had an equal number of contacts and everyone had equal influence. Others were placed into one of the “centralized” networks, in which a single opinion leader was connected to everyone, giving that person much more influence in the group. Each of the networks contained 40 participants. Finally, Centola had several hundred subjects participate in a “control” group, without any social networks.

In the study, all of the participants were given a series of estimation challenges, such as guessing the number of calories in a plate of food. They were given three tries to get the right answer. Everyone first gave a gut response.

Then, participants who were in social networks could see the guesses made by their social contacts and could use that information to revise an answer. They could then see their contacts’ revisions and revise their answers again. But this time it was their final answer. Participants were awarded as much as $10 based on the accuracy of their final guess. In the control group, participants did the same thing, but they were not given any social information between each revision.

“Everyone’s goal was to make a good guess. They weren’t paid for showing up,” Centola says, “only for being accurate.”

Patterns began to emerge. The control groups initially showed the classic wisdom of the crowd but did not improve as people revised their answers. Indeed, if anything, they got slightly worse. By contrast, the egalitarian networks also showed the classic wisdom of the crowd but then saw a dramatic increase in accuracy. Across the board, in network after network, the final answers in these groups were consistently far more accurate than the initial “wisdom of the crowd.”

“In a situation where everyone is equally influential,” Centola says, “people can help to correct each other’s mistakes. This makes each person a little more accurate than they were initially. Overall, this creates a striking improvement in the intelligence of the group. The result is even better than the traditional wisdom of the crowd! But, as soon as you have opinion leaders, social influence becomes really dangerous.”

In the centralized networks, Centola found that, when the opinion leaders were very accurate, they could improve the performance of the group. But even the most accurate opinion leaders were consistently wrong some of the time.

“Thus,” Centola says, “while opinion leaders can sometimes improve things, they were statistically more likely to make the group worse off than to help it.

“The egalitarian network was reliable because the people who were more accurate tended to make smaller revisions, while people who were less accurate revised their answers more. The result is that the entire crowd moved toward the more accurate people, while, at the same time, the more accurate people also made small adjustments that improved their score.”

Engineers and doctors

These findings on the wisdom of crowds have startling real-world implications in areas such as climate-change science, financial forecasting, medical decision-making, and organizational design.

For example, while engineers have been trying to design ways to keep people from talking to each other when making important decisions in an attempt to avoid groupthink, Centola’s findings suggest that what matters most is the network. A group of equally influential scientists talking to one another will likely lead to smarter judgments than might arise from keeping them independent.

He is currently working on implementing these findings to improve physicians’ decision-making. By designing a social network technology for use in hospital settings, it may be possible to reduce implicit bias in physicians’ clinical judgments and to improve the quality of care that they can offer.

Whether new technologies are needed to improve the way the groups talk to each other, or whether we just need to be cautious about the danger of opinion leaders, Centola says it’s time to rethink the idea of the wisdom of crowds.

“It’s much better to have people talk to each other and argue for their points of view than to have opinion leaders rule the crowd,” he says. “By designing informational systems where everyone’s voices can be heard, we can improve the judgment of the entire group. It’s as important for science as it is for democracy.”

Partial support for the work came from the Robert Wood Johnson Foundation.

Source: University of Pennsylvania

Ouvir o cacique (O Globo)


12/03/2010 10:14


É muito simples entender o que é a Fundação Cacique Cobra Coral. Trata-se de organização que se declara beneficente — e não há qualquer prova em contrário — que se atribuiu a missão de “minimizar catástrofes” avisando as autoridades com antecedência. Claro, entender é uma coisa, acreditar é outra. Mas também não falta quem acredite, e, parece, com boas razões.

A fundação foi criada por um certo Angelo Scritori, que morreu em 2002, com alegados 104 anos. Ele recebia os avisos da iminência de desastres naturais do Padre Cícero. Pouco antes de morrer, avisou à praça que seria sucedido pela filha, Adelaide, cujo contato com o outro lado passaria a ser o Cacique Cobra Coral.

Este se comunica com ela falando com sotaque de caboclo brasileiro, embora seja um índio americano Ao avisar sobre a substituição, Padre Cícero informou que o cacique também teria sido, em outras encarnações (se essa é a palavra certa, tratando-se de um espírito), Abraham Lincoln e Galileu Galilei. O leitor não deve ver esse dado com estranheza — até mesmo porque, se é cidadão de pouca fé, francamente, não tem qualquer razão para continuar lendo este artigo.

Mas parece que gente de muita fé não falta. O governo de São Paulo, por exemplo, tem contrato — sem valor financeiro — com a fundação desde 2005. Recebe aviso sobre catástrofes naturais a caminho, com tempo de tomar providências. Se as toma, não se sabe, mas isso não é problema para d. Adelaide.

Ela é bem-sucedida corretora de imóveis, moradora na região próspera dos Jardins de São Paulo. Há algum tempo, definiu com clareza o seu próprio papel como anunciadora de catástrofes: “Funcionamos como uma espécie de air bag. Reduzimos os danos, mas as autoridades têm de fazer a parte delas. O cacique não pode servir de muleta para os homens.”

Talvez como prova disso, a fundação já teve convênio com a Prefeitura de São Paulo, mas o rompeu na gestão do prefeito Gilberto Kassab, porque ele acabara com uma verba destinada a combater causas de desastres climáticos.

Seja como for, o prestígio da Cobra Coral vai além de São Paulo. Em novembro de 2008, a Comissão de Ciência e Tecnologia do Senado aprovou um convite a Adelaide para ir até lá discutir o apagão em 18 estados. Não sei se chegou a ir, não me lembro de notícia disso, mas o convite existiu.

Aqui no Rio, a fundação está discutindo com a Prefeitura a renovação de um convênio — que não envolve qualquer pagamento — pelo qual a fundação profetiza tempestades e assim ajuda a diminuir os seus efeitos. Sendo de graça, por que não ouvir o cacique?

Texto publicado no Globo de hoje.

Antropólogo cria primeiro Centro de Medicina Indígena em Manaus (G1)

Pesquisador idealizou projeto após uma parente se curar de uma picada de cobra com tratamento que uniu saber científico e indígena. 

Indígena Manoel Lima assumir a função de “Grande Kumu”, no Amazonas (Foto: Ive Rylo/G1 AM)

Indígena Manoel Lima assumir a função de “Grande Kumu”, no Amazonas (Foto: Ive Rylo/G1 AM)

A sabedoria herdada de seus avós a longo de 85 anos fez o indígena Manoel Lima assumir a função de “Grande Kumu”, pajé do povo Tuyuka, no Amazonas. Ele é um dos indígenas que, junto com um dos membros do Colegiado Indígena, do Programa de Pós-graduação em Antropologia Social da Universidade Federal do Amazonas (Ufam), criaram o Bahserikowi´i”, ou Centro de Medicina Indígena da Amazônia. O espaço abre as portas para o público em Manaus nesta terça-feira (6). O local não conta com apoio ou interferência das secretarias de saúde do governo e prefeitura.

“Não é para abandonar a indicação dos médicos [tradicionais] mas para agregar”, disse o antropólogo João Paulo Tukano que idealizou o projeto após uma parente se curar de uma picada de cobra com um tratamento que uniu saber científico e indígena.

De acordo com o idealizador do centro, o espaço busca aliar tratamento milenares utilizados nas aldeias para ajudar a pessoas doentes, indígenas ou não, sem esquecer da medicina tradicional.

“Aqui é mais uma opção de tratamento de saúde, baseado em técnica e tecnologias indígenas usadas de geração em geração”, disse Tukano.

Nesta terça-feira, o kumu Tuyuka começa a oferecer serviços. Além dele, pajés das etnias Tikuna, Satere Mawé, Baniwa, Apurinã estarão disponíveis. No local, os tratamentos são feitos de duas formas, iniciando pelo Bahsesé – uma espécie de benzimento – seguido da indicação dos medicamentos.

“O Bahsesé não é ficar rezando. O Kumu aciona princípios curativos contidos nos vegetais e nos animais. É nessa hora, quando ele fica falando, que ele invoca os princípios dentro de um elemento para ver o que pode passar para a pessoa para curar”, disse


O prédio foi cedido pela Coordenação das Organizações Indígenas da Amazônia Brasileira (Coiab). A manutenção do local é feita pelos próprios indígenas e por amigos. A venda de artesanato e de medicamentos caseiros serão feitas no local para auxiliar na manutenção do Centro. Os atendimentos serão feitos de segunda a sexta-feira das 9h as 13h, na rua Bernardo Ramos, 97, Centro de Manaus. O valor de cada atendimento é R$ 10.

Kumu Manoel

Para ser um grande kumu da aldeia, Manoel Lima contou que foi treinado com os avós desde muito cedo, segundo conta.

“Aprendi com os meus avós, quando tinha seis anos de idade. Desde cedo fui treinado. Nós ficávamos 4 meses longe da aldeia, dentro do mato, onde não tem barulho para se dedicar só ao aprendizado da cura. Treinamos para ser grande Kumu”, disse.

Os Kumus vivem em São Gabriel da Cachoeira, nas comunidades de Taraque, Iauaritê e Paricachoeirinha. Por conta da dificuldade de acesso às aldeias e à falta de maiores investimentos na saúde, os indígenas reclamam que quase não têm acesso aos tratamentos da medicina “branca tradicional”. Por isso, as técnicas de cura herdada dos ancestrais ainda hoje são importantes e passadas de pai para filho dentro das aldeias.

Produtos feitos a base de ervas são vendidos no local, em Manaus (Foto: Iver Rylo/G1 AM)

Produtos feitos a base de ervas são vendidos no local, em Manaus (Foto: Iver Rylo/G1 AM) 

“Com essa novidade, eu estou muito feliz, é uma iniciativa inédita. Eu já oferecia os tratamentos em casa há muito tempo, não era divulgado e agora é uma coisa grande”, disse o kumu.

Ele garante que existem curas para todos os tipos de enfermidades, inclusive para o que os médicos estão chamando de “mal do século”: a ansiedade e depressão.

“Tratamos desde doenças da cabeça até problemas no útero e menstruação desregulada”, garantiu.


A necessidade de agregar e respeitar variadas formas de tratamentos e saberes, dando visibilidade ao conhecimento indígena foi despertada em João Paulo há sete anos, quando a sobrinha dele quase teve a perna amputada.

“O médico decidiu amputar a perna dela. Meu pai disse que não precisava e poderíamos fazer [o tratamento] em conjunto, os médicos e nós indígenas. O médico não aceitou e disse ‘o senhor não estudou nenhum dia, eu estudei 8 anos’. Fiquei muito abatido, triste e nervoso. Pensei melhor e esta foi uma motivação para eu estudar e tratar ele de igual para igual. E caminhei mais para antropologia”, disse João Paulo.

O caso repercutiu, foi para a justiça, o governo entrou em cena e uma nova equipe de médicos foi formada no Hospital Universitário Getúlio Vargas. À época, No dia 15 de janeiro, Ministério Público Federal chegou a recomendar a um dos hospitais onde a menino foi levada que promovesse a articulação dos conhecimentos da medicina comum com o conhecimento e as práticas tradicionais de saúde dos índios tukano.

“Com a outra equipe pudemos dialogar. O médico quis ouvir meu pai e meu pai falou o que gostaria de fazer e eles respeitaram. Primeiro sugerimos tratamento com plantas, o médico disse que não aconselhava e listou os motivos, depois sugerimos com água mineral e foi acordado num diálogo”, disse.

O tratamento dos médicos em parceira com os pajés Tukano deu certo. A menina não teve a perna amputada e hoje, com 19 anos, tem muita história para contar. “Temos vários casos, meus parentes sofrem. Esse veio à tona porque eu briguei”, disse o antropólogo.

Além o desconhecimento da medicina tradicional aos tratamentos indígenas, a dificuldade dos povos indígenas em conseguir atendimento de saúde na capital também motivou a criação do centro.

“Um dos nossos objetivos é disponibilizar o acesso a tratamento para indígenas que estão em Manaus, porque muito reclamam da dificuldade de chegar as unidades de saúde. É muito comum acontecer do indígena não conseguir tratamento”, lamentou o antropólogo.

Centro fica em uma casa antiga no Centro de Manaus (Foto: Ive Rylo/G1 AM)

Centro fica em uma casa antiga no Centro de Manaus (Foto: Ive Rylo/G1 AM)

Climate Science Meets a Stubborn Obstacle: Students (New York Times)

“It’s his website,” she said.

 Mr. Sutter during his Advanced Placement environmental science class. He was hired from a program that recruits science professionals into teaching. Credit: Maddie McGarvey for The New York Times

For his part, Mr. Sutter occasionally fell short of his goal of providing Gwen — the most vocal of a raft of student climate skeptics — with calm, evidence-based responses. “Why would I lie to you?” he demanded one morning. “It’s not like I’m making a lot of money here.”

She was, he knew, a straight-A student. She would have had no trouble comprehending the evidence, embedded in ancient tree rings, ice, leaves and shells, as well as sophisticated computer models, that atmospheric carbon dioxide is the chief culprit when it comes to warming the world. Or the graph he showed of how sharply it has spiked since the Industrial Revolution, when humans began pumping vast quantities of it into the air.

Thinking it a useful soothing device, Mr. Sutter assented to Gwen’s request that she be allowed to sand the bark off the sections of wood he used to illustrate tree rings during class. When she did so with an energy that, classmates said, increased during discussion points with which she disagreed, he let it go.

When she insisted that teachers “are supposed to be open to opinions,” however, Mr. Sutter held his ground.

“It’s not about opinions,” he told her. “It’s about the evidence.”

“It’s like you can’t disagree with a scientist or you’re ‘denying science,”’ she sniffed to her friends.

Gwen, 17, could not put her finger on why she found Mr. Sutter, whose biology class she had enjoyed, suddenly so insufferable. Mr. Sutter, sensing that his facts and figures were not helping, was at a loss. And the day she grew so agitated by a documentary he was showing that she bolted out of the school left them both shaken.

“I have a runner,” Mr. Sutter called down to the office, switching off the video.

He had chosen the video, an episode from an Emmy-winning series that featured a Christian climate activist and high production values, as a counterpoint to another of Gwen’s objections, that a belief in climate change does not jibe with Christianity.

“It was just so biased toward saying climate change is real,” she said later, trying to explain her flight. “And that all these people that I pretty much am like are wrong and stupid.”

Classroom Culture Wars

As more of the nation’s teachers seek to integrate climate science into the curriculum, many of them are reckoning with students for whom suspicion of the subject is deeply rooted.

In rural Wellston, a former coal and manufacturing town seeking its next act, rejecting the key findings of climate science can seem like a matter of loyalty to a way of life already under siege. Originally tied, perhaps, to economic self-interest, climate skepticism has itself become a proxy for conservative ideals of hard work, small government and what people here call “self-sustainability.”

A tractor near Wellston, an area where coal and manufacturing were once the primary employment opportunities. Credit: Maddie McGarvey for The New York Times

Assiduously promoted by fossil fuel interests, that powerful link to a collective worldview largely explains why just 22 percent of Mr. Trump’s supporters in a 2016 poll said they believed that human activity is warming the planet, compared with half of all registered voters. And the prevailing outlook among his base may in turn have facilitated the president’s move to withdraw from the global agreement to battle rising temperatures.

“What people ‘believe’ about global warming doesn’t reflect what they know,” Dan Kahan, a Yale researcher who studies political polarization, has stressed in talks, papers and blog posts. “It expresses who they are.”

But public-school science classrooms are also proving to be a rare place where views on climate change may shift, research has found. There, in contrast with much of adult life, it can be hard to entirely tune out new information.

“Adolescents are still heavily influenced by their parents, but they’re also figuring themselves out,” said Kathryn Stevenson, a researcher at North Carolina State University who studies climate literacy.

Gwen’s father died when she was young, and her mother and uncle, both Trump supporters, doubt climate change as much as she does.

“If she was in math class and teacher told her two plus two equals four and she argued with him about that, I would say she’s wrong,” said her uncle, Mark Beatty. “But no one knows if she’s wrong.”

As Gwen clashed with her teacher over the notion of human-caused climate change, one of her best friends, Jacynda Patton, was still circling the taboo subject. “I learned some stuff, that’s all,’’ Jacynda told Gwen, on whom she often relied to supply the $2.40 for school lunch that she could not otherwise afford.

Jacynda Patton, right, during Mr. Sutter’s class. “I thought it would be an easy A,” she said. “It wasn’t.”Credit: Maddie McGarvey for The New York Times

Hired a year earlier, Mr. Sutter was the first science teacher at Wellston to emphasize climate science. He happened to do so at a time when the mounting evidence of the toll that global warming is likely to take, and the Trump administration’s considerable efforts to discredit those findings, are drawing new attention to the classroom from both sides of the nation’s culture war.

Since March, the Heartland Institute, a think tank that rejects the scientific consensus on climate change, has sent tens of thousands of science teachers a book of misinformation titled “Why Scientists Disagree About Global Warming,” in an effort to influence “the next generation of thought,” said Joseph Bast, the group’s chief executive.

The Alliance for Climate Education, which runs assemblies based on the consensus science for high schools across the country, received new funding from a donor who sees teenagers as the best means of reaching and influencing their parents.

Idaho, however, this year joined several other states that have declined to adopt new science standards that emphasize the role human activities play in climate change.

At Wellston, where most students live below the poverty line and the needle-strewn bike path that abuts the marching band’s practice field is known as “heroin highway,” climate change is not regarded as the most pressing issue. And since most Wellston graduates typically do not go on to obtain a four-year college degree, this may be the only chance many of them have to study the impact of global warming.

But Mr. Sutter’s classroom shows how curriculum can sometimes influence culture on a subject that stands to have a more profound impact on today’s high schoolers than their parents.

“I thought it would be an easy A,” said Jacynda, 16, an outspoken Trump supporter. “It wasn’t.”

God’s Gift to Wellston?

Mr. Sutter, who grew up three hours north of Wellston in the largely Democratic city of Akron, applied for the job at Wellston High straight from a program to recruit science professionals into teaching, a kind of science-focused Teach for America.

He already had a graduate-level certificate in environmental science from the University of Akron and a private sector job assessing environmental risk for corporations. But a series of personal crises that included his sister’s suicide, he said, had compelled him to look for a way to channel his knowledge to more meaningful use.

The fellowship gave him a degree in science education in exchange for a three-year commitment to teach in a high-needs Ohio school district. Megan Sowers, the principal, had been looking for someone qualified to teach an Advanced Placement course, which could help improve her financially challenged school’s poor performance ranking. She hired him on the spot.

Mr. Sutter walking with his students on a nature trail near the high school, where he pointed out evidence of climate change. Credit: Maddie McGarvey for The New York Times 

But at a school where most teachers were raised in the same southeastern corner of Appalachian Ohio as their students, Mr. Sutter’s credentials themselves could raise hackles.

“He says, ‘I left a higher-paying job to come teach in an area like this,’” Jacynda recalled. “We’re like, ‘What is that supposed to mean?”’

“He acts,” Gwen said with her patented eye roll, “like he’s God’s gift to Wellston.”

In truth, he was largely winging it.

Some 20 states, including a handful of red ones, have recently begun requiring students to learn that human activity is a major cause of climate change, but few, if any, have provided a road map for how to teach it, and most science teachers, according to one recent survey, spend at most two hours on the subject.

Chagrined to learn that none of his students could recall a school visit by a scientist, Mr. Sutter hosted several graduate students from nearby Ohio University.

On a field trip to a biology laboratory there, many of his students took their first ride on an escalator. To illustrate why some scientists in the 1970s believed the world was cooling rather than warming (“So why should we believe them now?” students sometimes asked), he brought in a 1968 push-button phone and a 1980s Nintendo game cartridge.

“Our data and our ability to process it is just so much better now,” he said.

In the A.P. class, Mr. Sutter took an informal poll midway through: In all, 14 of 17 students said their parents thought he was, at best, wasting their time. “My stepdad says they’re brainwashing me,” one said.

Jacynda’s father, for one, did not raise an eyebrow when his daughter stopped attending Mr. Sutter’s class for a period in the early winter. A former coal miner who had endured two years of unemployment before taking a construction job, he declined a request to talk about it.

“I think it’s that it’s taken a lot from him,” Jacynda said. “He sees it as the environmental people have taken his job.”

And having listened to Mr. Sutter reiterate the overwhelming agreement among scientists regarding humanity’s role in global warming in answer to another classmate’s questions — “What if we’re not the cause of it? What if this is something that’s natural?” — Jacynda texted the classmate one night using an expletive to refer to Mr. Sutter’s teaching approach.

But even the staunchest climate-change skeptics could not ignore the dearth of snow days last winter, the cap to a year that turned out to be the warmest Earth has experienced since 1880, according to NASA. The high mark eclipsed the record set just the year before, which had eclipsed the year before that.

In woods behind the school, where Mr. Sutter had his students scout out a nature trail, he showed them the preponderance of emerald ash borers, an invasive insect that, because of the warm weather, had not experienced the usual die-off that winter. There was flooding, too: Once, more than 5.5 inches of rain fell in 48 hours.

The field trip to a local stream where the water runs neon orange also made an impression. Mr. Sutter had the class collect water samples: The pH levels were as acidic as “the white vinegar you buy at a grocery store,” he told them. And the drainage, they could see, was from the mine.

It was the realization that she had failed to grasp the damage done to her immediate environment, Jacynda said, that made her begin to pay more attention. She did some reading. She also began thinking that she might enjoy a job working for the Environmental Protection Agency — until she learned that, under Mr. Trump, the agency would undergo huge layoffs.

“O.K., I’m not going to lie. I did a 180,” she said that afternoon in the library with Gwen, casting a guilty look at her friend. “This is happening, and we have to fix it.”

After fleeing Mr. Sutter’s classroom that day, Gwen never returned, a pragmatic decision about which he has regrets. “That’s one student I feel I failed a little bit,” he said.

As an alternative, Gwen took an online class for environmental science credit, which she does not recall ever mentioning climate change. She and Jacynda had other things to talk about, like planning a bonfire after prom.

As they tried on dresses last month, Jacynda mentioned that others in their circle, including the boys they had invited to prom, believed the world was dangerously warming, and that humans were to blame. By the last days of school, most of Mr. Sutter’s doubters, in fact, had come to that conclusion.

“I know,” Gwen said, pausing for a moment. “Now help me zip this up.”

Após Trump sair do Acordo de Paris, Cacique Cobra Coral deixa de atender pedidos dos EUA (UOL Notícias)

02/06/2017, 20h54

2.jun.2017 - Post da Fundação Cacique Cobra Coral no Instagram

2.jun.2017 – Post da Fundação Cacique Cobra Coral no Instagram. Instagram/Reprodução

Em nota publicada no Instagram nesta sexta-feira (2), a Fundação Cacique Cobra Coral afirmou que deixará de prestar atendimentos climáticos aos EUA. A medida será mantida “enquanto perdurar a falta de bom senso do presidente Donald Trump com relação a retirada dos EUA do Acordo de Paris, rompendo o acordo global firmado em dezembro de 2015 com mais de 190 países para reduzir a emissão de gases que produzem o efeito estufa”.

A entidade esotérica diz, em seu site, que sua missão é “minimizar catástrofes que podem ocorrer em razão dos desequilíbrios provocados pelo homem na natureza”. Também diz ser orientada pelo Cacique Cobra Coral, “espírito que teria sido de Galileu Galilei e Abraham Lincoln”.

O presidente americano afirmou que pacto climático internacional é injusto, representa um enorme fardo econômico para os EUA e não seria eficaz o suficiente. Em seu discurso, a expressão “mudança climática” não foi mencionada sequer uma vez. Trump preferiu falar de mais dinheiro e empregos.

“O Acordo de Paris sobre o clima é simplesmente o mais recente exemplo de que Washington cedeu a uma resolução que penaliza os Estados Unidos para beneficiar outros países. Deixa os trabalhadores americanos, que eu amo, e o contribuintes absorverem o custo, em termos de perda de empregos, menores salários, fechamento de fábricas e enorme redução na produção econômica”, disse Trump.